Modbus message 6 modbus message details – Lenze ESVZAR0 RS-485 User Manual
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CMVMB401C
Modbus Message
6
Modbus Message Details
These abbreviations will be used throughout this section to illustrate the message structure:
R
Read
W
Write
RS
Response
SA
Slave Address (01 ... F7 hex)
EC
Exception Code
RH
Register Address (high byte)
RL
Register Address (low byte)
DxH Data (high byte)
DxL
Data (low byte)
CRCH Cyclic Redundancy Check (high byte)
CRCL Cyclic Redundancy Check (low byte)
6.1
Register Reading
6.1.1 Message structure for reading one 16-bit register
All registers except #1
R
SA
03
RH
RL
00
01
CRCH
CRCL
RS
SA
03
02
DH
DL
CRCH
CRCL
6.1.2 Message structure for reading two 16-bit registers
Registers 32, 60 and 64 only
R
SA
03
RH
RL
00
02
CRCH
CRCL
RS
SA
03
04
D1H
D1L
D2H
D2L
CRCH
CRCL
D1H and D1L are the high and low bytes of the first 16-bit register value (32, 60, 64)
D2H and D2L are the high and low bytes of the second 16-bit register value (33, 61, 65)
Example: Total Run-time Hours = 305419896 (12345678h)
Register #60 (low word of total run-time hours) = 5678h
Register #61 (high word of total run-time hours) = 1234h
R
SA
03
00
3C
00
02
CRCH
CRCL
RS
SA
03
04
56
78
12
34
CRCH
CRCL